Centrifugal solvent extraction



'7 Sheets-Sheet 1 Filed Dec. 21. 1960 July 13, 1965 J. F. H ERNDON 3,194,400

CEN'I'RIFUGAL SOLVENT EXTRACTION FiledDec. 21. 1960 '7 Sheets-Sheet 2 I I ig ff )i f y' 022/ July 13, 1965 J. F. HERNDON 3,194,400

CENTRIFUGAL SOLVENT EXTRACTION Filed Dec. 21, 1960 7 Sheets-Sheet 3 45 I if I A ATTORNEYJ J- F. HERNDON CENTRIFUGAL SOLVENT EXTRACTION July 13, 1965 '7 Sheets-Sheet 4 Filed Dec. 21. 1960 July 13, 1965 J. F. HERNDON CENTRIFUGAL SOLVENT EXTRACTION Filed D90- 21. 1960 7 Sheets-Sheet 5 4/ 67 3/ 6 a H 9- H 72 f2 72 a be *0 63 9 J'ofirz $223229 ATTORNEYS Ju y 1965 J. F. HERNDON CENTRIFUGAL SOLVENT EXTRACTION 7 Sheets-Sheet; 6

Filed Dec. 21. 1960 III! III I III/111 A III July 13, 1965 J. F. HERNDON 3,194,400

CENTRIFUGAL SOLVENT EXTRACTION Filed Dec. 21. 1960 v 7 Sheets-Sheet 7 ACID BASE | ENTOR NEYS United States Patent 3,194,400 CENTRIFUGAL SOLVENT EXTRACTION John F. Herndon, Park Chester Hills, West Chester, Pa.,

assignor to Malvern Institute for Psychiatric and Alcoholic Studies, Malvern, Pa., a non-profit corporation of Pennsylvania Filed Dec. 21, 1960, Ser. No. 77,422 11 Claims. (Cl. 210-203) The present invention relates to chromatographic separation devices of the character which employ a separating medium such as paper, starch, ion exchange medium, or the like, with application of centrifugal force,

and with introduction of a development liquid which by difference in solubility causes separation of a material to be separated.

A purpose of the invention is to reduce the time required for chromatographic separation for the purpose of analysis, and industrial separation.

A further purpose is to permit chromatographic separations selectively at high speed, low speed or under static conditions using the same mechanism.

A further purpose is to permit chromatographic separation in the same mechanism by using a plurality of different separating media, a plurality of different development liquids, or both.

A further purpose is to produce a more even solvent front and a more clearly defined component band so that different components can be more accurately scanned for area determination.

A further purpose is to secure better control of delivery of development liquid in centrifugal chromatography.

A further purpose is to reduce lateral diffusion of development liquid during its outward flow. It is particularly desirable to reduce this feature which is characteristic of disc centrifugal chromatography.

A further purpose is to apply centrifugal chromatography to industrial solvent extraction.

A further purpose is to mount on a rotating shaft or the like a generally outwardly or radially extending channel having sides or defining generally radially extending walls and to position insaid channel and between said walls a separating medium such as paper, starch, ion exchange resin or the like.

A further purpose is to provide relatively converging side walls of the channel to hold the separating medium in place.

A further purpose is to provide a recess at one side of the channel or passage, suitably with supporting projections for the separating medium, so as to prevent the formation of puddles in case excess of solvent is fed.

A further purpose is to provide a plurality of radial channels around a rotor, and to distribute development liquid separately to each of the channels, permissibly through a separate passage or through a separate wicklike feeder for each channel.

A further purpose is to prevent dripping of condensed development liquid on the surface of the separation medium, preferably by providing a cover which will carry any condensed droplets radially outwardly.

A further purpose is to introduce the separating me dium for a plurality of radial channels as a unit, suitably in the form of a spoked wheel having a hub and a rim, the spoke elements fitting into the respective channels.

A further purpose is to introduce the separation medium in the form of a disc having radially extending ribs which enter the channels and convey the development liquid.

A further purpose is to provide one or more separate channels on a rotor, each of which has a strip of radially extending parallel sided separating medium such as paper, starch, ion exchange resin or the like, and to supply development liquid which may permissibly also contain material to be separated to the channels independently, thus permitting the use of different separating media, and/or development liquids and/ or different materials to be separated in the respective channels.

A further purpose is to provide catch means at the radial outer ends of the channels which are individual to the different channels.

A further purpose is to surround a channel or channels of a rotor with a catch ring and to substitute other catch rings successively as in a sequence in order to take off different fractions.

A further purpose is to provide different channels at different axial positions along the rotor and different catch rings for the different channels located at the different axialpositions.

A further purpose is to permit utilization of centrifugal chromatography in more precise control of product composition and quality.

A further purpose is to adapt ion exchange methods of centrifugal chromatography to broad ranges of commercial separation and purification, including the purification of brackish water, sea water, brine, and polluted water.

A further purpose is to change the center of centrifugal rotation.

A further purpose is to pre-wet the fiber disc wicks with development liquid before starting the separation.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the stand-points of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURES 1 to 6 inclusive show a preferred embodiment of the device of the invention for noncontinuous operation.

FIGURE 1 is a top plan view of the device of the invention with the cover removed and the housing partly broken away.

FIGURE 2 is an axial section of the device of FIG- URE 1 on the line 2-2 with the housing and cover in place.

FIGURE 3 is an enlarged fragmentary axial section of the device of theinvention through one of the channels which holds the medium.

FIGURE 4 is a fragmentary horizontal section on the line 44 of FIGURE 3.

FIGURE 5 is a fragmentary horizontal section on the line 5 of FIGURE 3 omitting the metallic parts.

FIGURE 6 is an enlarged fragmentary section on the line 6-6 of FIGURE 3.

FIGURE 7 is a view similar to FIGURE 6 showing a variation.

FIGURE 8 is a diagrammatic top plan view showing the insertion of the paper or other medium in the form of a wheel which has an outer rim which will conveniently be removed.

FIGURE 9 is a view similar to FIGURE 5 which shows a variation in which separate strips of medium are employed.

FIGURE 10 is a fragmentary top plan view of a modified form of chromatographic apparatus according to the invention which discharges into a collecting ring common to all channels.

FIGURE 11 is a section on the line 11-11 of FIG- URE 10.

FIGURE 12 is a view similar to FIGURE 11 showing a series of collecting rings which are successively moved into place opposite the outer rim of the chromatographic apparatus as different fractions are being discharged.

'URE 18. V

FIGURE'ZO-is a plan view'showing multiple rotational centerchromatography according to the invention.

FIGURE 21 is a fragmentary plan view of a variant form of chromatographic apparatus according to thein vention which has separate channels and separate feeds.

FIGURE 13 is a fragmentary axial sectionthrough a variantform of chromatographic apparatus according to theinvention in whicha star-like distributor is used at the hub. 7

FIGURE 14' is a section on the line .14-l4- URI-E13 omitting the ceutral'adapterj FIGURE 15' is a top plan 'view of a variant'form of chromatographic apparatus according to, the inven: tion using a Chinese hat type'of cover.

FIGURE 16 is an URE 15. 7

FIGURE 17 is a fragmentary axialsection of a chromatographic apparatus according to the invention in which the'rotor has been inverted to permit the use of a disctype of paperor other medium.

FIGURE 18 is a plan view of a modified form of'chromatograpliic disc which has liquid directing ribseittending radiallyand impregnated into the paper or other mediurn to form channels.

FIGURE 19 is asection on' the line l9-19 of pro foreach channel.-

FIGURE. 22 is an enlarged fragmentary section on the line 22-22 of FIGURE 21.

" FIGUREZB is a fragmentary plan section on the line 2 3-23-jof FIGURE 22. v

FI GURE'Z I is a section on the line 24Z4 of FIG- URE 22. v V I FIGURE 25 is a seriesoffcurves useful in evaluating theresults of the device of the invention. 7

of FIG- a'xialsection of the device of PlG-- 10 i The present invention'makes: it' possiblejtogreatly re- 1 duce .the time requirdgbcause the chr'ornatographic'separation; is much better controlled, 3 the separation areas/ are more precisely? defined Land xiii-fact are generally: 5 bands, which can be convenientlyestimated qualitative FIGURE '26. is a diagrammatic planview showiug a' m series of chromatographsobtained for amino acids according to the inventionand of resultsobtained. i I 7 V 1 In the prior art, centrifugal chromatography. has been usedas a means of analytical separation of components In usual practice, a disc g of filter paper or the like, preferably of the type having random fiberdirection, has usually been-rotated'ona' vertical axis, the filter paper during rotation being sub-F v stantially free from support or supported by plates or by due to difierence in solubility.

fingers orsu'pported by an outside rim and an inside hub.

The samples have usually been spotted on tothe paper illustrative of the character to thesdisc: 29.": The adapter "has at various points around the circumference adjacent'to the axis. The liquid :used to develop the. sample,'suitably a solvent or a butter, has been introduced by inject i 1 ing at the center orby spraying at the hub. While these techniques have olfered promise, the control has beenso diflicult that results other than qualitative results have been very difficult and inconsistent. a

' Among the difliculties encountered have been the fol lowing; V I

(1) One dilficulty has been that the paper-.tends to break ,or tear near the hub and destroy the further experiment.

(2) Separationsof distinct components like different amino acids have often not been precise, but the areas have overlapped and comebtailed so that the lines of separation have been ill-defined or indefinable. I (3) In many cases the tendency has been to spread laterally into ill-defined configurations which do not lend themselves readily to separation, identification and quantitative estimation.

(4) Just as the areas'ofseparation of components have been-uneven, the solvent front has tended to be uneven and is practically always. elliptical or scalloped, making it diificult to determine the exact solvent front diameter which is a critical feature in determining the positions which different components should assume (R (5) The devices of the prior art have not been adaptable to operation with a plurality of different separating media or a plurality of different development liquidsin' a single separation, which may. operate on differentmate- V,

rials to be separated;

(6) It hasalso .notbeen practicalin prior-art devices to use the samemechanism' for. both stationary chromatography and also centrifugal -,'chromatography f(7-) The .devices of the prior art have not made it possible to producelarge quantity industrial centrifiagal,

chromatographic separations. 1

ly and quantitatively; V .The invention also makes: it possible.

to control muchmore precisely 'thetshape of the i'solvent' frontpwhich:is

important in chromatographic separations... 1' t The invention also reduces. the difiic al spreadingiof separationar'easi Comet-tailing is no longer a problem.

it is possible, in accordanceg fwith the 'present' inven L I tion, to operate vwith a plurality of different separating. f media, and/or a "plurality of different solvents, *1 in the same mechanism.

The invention also lends itself to fractional separations. The device of the invention is particularlya-daphable for large scale industrial centrifugal chromatographic separations p The invention differences in' center of'rotation, 1

In the :tdevice-of the invention; direction prior art. 1

Considering nowthejdrawings in; detail, in FIGURES w :1 to 6 i illustratea disc. 20-;whic'h is'mou'nt'edon a shaft; 21 turning at a suitable variably}controlledfspeedon a. vertical axis, preferably by a-rmotor combinedwithija.

' da pterr- 23 'secured 1' hub onion ;whichl speed 'redu'cen'whi'ch shaft. mounts surrounds the shaftiland is 'anc-hored'th rcon .by s 24, and above the hublhasva' flange z 7 the bottom :of disc 20 suitably in arecc' s r w of opening-27 tat theacenteiz-otidiscii20.i,. Above the stub'shafit portion =2;6.th adapter l es the extension 26 is 1.;adistributor cup @35 {which *h sjan interior-tanksfikcxtending up above andzsurroundin'g'the ports 33. The: cup 351s heldin z-place bywasherLST V and nut 37' threaded ;on threaded portion 30*by: the. wada'pter. t f I The cup; has -an.lupward-ly converging interior annu lar well-1.33 which under; centrifugal forcei'tends to' carry any. liquid in the. cupgto the bottom; and hasa down-- I wandlyj and outwardly slopingbottom wa=1l740 tendingto feed liquid downwardly and outwardly and atf-theo-uter circumference hasjd'ownwardly and-"outwardly j'extending ports 41"which are injthepreferred embodiment aligned;

ties through' later-i also 'much' more precisely'controls the" feed of solvent so that difiicultyflthroughiexcessive solvent feed .or: thorough uneven :solventteed .iseliminated.

Chromatographic separations can be carried out with;

difiiculties through-the? of the paper fiber are less :seriousfthanin the.

hichrests on: Q A v 'flansej; '25fthere islastub shaft extension :26 which is of key, formation; suitably flattened, and conforms to the shape with the middle of the radial inner end of radially extendin-g channels 4,2. in the disc 20.

In the preferred embodiment the radially extending channels at the inner end communicate with an annular recess 43 into which the cup 35 fits.

The upwardly converging form of the wall 38 of the cup and the downwardly diverging form of the ports 41 tends to overcome :air binding, especially at lower speeds, which has been a serious difficulty in previous efforts to provide uniform feed of the development liquid.

Each of the radial grooves in the preferred form at its inner end is of rectangular formation as shown at 44, but at a radial outer portion it has upwardly converging side walls as shown at 45. The upwardly converging side walls 45 engage and hold in place radially extending strips 46 of separation medium, which may be a paper such as .filter paper, or may be starch suitably impregnated on a base such as paper, or may be ion exchange resin suitably impregnated on .a base such as paper, or may be deposits of starch or ion exchangeresin in the radial groove.

It will be evident that the means of supporting the paper or other separation medium by the engagement with the walls is very convenient in avoiding difiiculty through bulging of the paper strip under conditions of expansion when the paper becomes moistened at the inner end or over a portion of its length and tends to grow. The paper should be wide enough to just fill the groove 45.

At the inner end at the bottom of recess 43 is placed a hub 47 of separation medium such as paper, which in one embodiment of the invention (FIGURE 5) is integrally connected to the strips 46 as the hub of a wheel is connected to the Spokes. For this purpose a wheellike separation medium replacement unit may be used as shown in FIGURE 8 which has the hub 47, the spokeiike strips 46 and an outer rim 48 which will be convenient-1y removed after installation of the paper ribs. Thus the rim will serve to hold the components together when the wheel is applied to the disc. On both sides of the hub portion 4-7 of the separation medium I preferably place washers 5t) and 51 (FIGURE 5) of a suitable fibrous dispersing medium, such as fiber glass fabric or felt, which tends to perform a wick action in allowing the separation liquid to distribute.

In find that the time of separation can be cut to about one-quarter in many cases by pro-wetting the fiber glass fabric or felt wicks with development liquid before starting the separation.

In the preferred embodiment the bottom of the channel 42 is cut awayv at the middle to form a radially extending recess '52 down the middle of the channel 42, which permits excess of development liquid to flow outw-ardly without forming pools and tending to interfere with the techniques of the separation of the components. If desired several different recesses 52 may be employed as shown in FIGURE 7 separated by supporting projections or ribs 53.

At the outer end each of the channels communicates by port 54 with a collecting cup 55 which preferably downwardly diverges as shown (FIGURE 3) to hold the liquid at a point remote from the channel and avoids a loss of material from the cup under centrifugal force.

It will be evident that each of the channels if desired can have a wholly separate separatingmedium, and for example these may be different grades of paper, or one may be paper and .another paper impregnated starch and others may be different grades of paper impregnated with ion exchange materials of different characters or different cellulose derivatives. This is shown in FIG- URE 9, where it will be evident that a strip of separation medium 46 for each channel is carried into the radial inner end between the fiber glass washers 5d and 51 and this strip 46' may be separate from strips in other channels.

It is decidedly preferable .to use separating media which are of consistent quality from the standpoint of chromatographic diffusion. In some cases paper having random fiber distribution may be employed. In other instances the fiber will have radial fiber distribution in the different channels and this may be accomplished by using separate paper strips for the different channels.

In some instances the collector cups can be eliminated, and where all channels are discharging the same composition, a collector ring may surround the outside of the disc as shown in FIGURES 10 and 11.

In some instances the fractions will be of different compositions, and in FIGURE 12 I illustrate a succession of different collector rings 55', 55 55 etc., which are progressively moved into position surrounding the channels of the disc as the operation proceeds.

It will be evident that the disc need not be flat but can be cone shaped, convex or concave, as desired.

In some instances it is preferable to employ controllable wick feeding directly to the radial inner end at the center of each channel. In FIGURES 13 and 14 I illustrate such a device, in which a paperhub 47 of star-like configuration receives the development liquid from any suitable feeding device, here a cup 56 having feeding openings 56' extending radially in line with the channels, and by wick action deposits it at an apex 57 over the inner end of the paper strip 46 of each channel at the middle thereof. The apex suitably overlaps the inner end of the strip of separation medium.

It will be evident that various other contours for the feeding projections 57 rather than the star pointed form can be used to give various solvent characteristics as required and numerous forms have been tested, such as various curves.

With certain volatile solvents there is a considerable tendency to vaporize and condense and deposit droplets which may fall on the separation medium and confuse the results. With this purpose in view a suitably conical cover 58 is preferred which will cause any such droplets to flow to the outer edge without falling. This is best seen in FIGURES 15 and 16.

In some cases the user may prefer to use a disc of separating medium as in the prior art, and with this idea in view the disc can be inverted by removing the adapter and putting the adapter through the central opening from the opposite end, as shown in FIGURE 17, and placing a disc 59 of filter paper or other suitable separating medium on top of the flatsurface, which gives support.

The principles of the invention can be readily embodied in a disc of separation media 60 such as paper, as shown in FIGURES 18 and 19, by separating it by means of a series of radially extending ribs 61 of phenolic resin or other material impregnated into the paper or other me dium. The ribs 61 are impervious or substantially impervious to the developing liquid. The ribs 61 define the sides of the radial channels 42' as previously discussed. This can be applied using the reverse face of the metallic disc as in FIGURE 17.

The principles of the invention can be embodied in twodimensional centrifugal chromatography as illustrated best in FIGURE 20. In this form the initial limits of radial channels on a paper disc are shown at 63 and the initial axis of rotation of the disc is at 64. Various specimens of known chemicals are spotted at 65, 65', 65 and 65 and various specimens of unknowns are spotted at 66, 66, 66 66 and 66 radially opposite.

The known compounds after treatment with the development liquid produce various characteristics Rf areas 67, 67', 6'7 and 67 in a known time. The unknowns separate into various separate R areas 68, 68' and 68 etc., of which only the areas for one spot 66 are shown.

R; is equal to the movement of the specimen band divided by the movement of the advancing front of separation liquid.

The paper is then suitably separated along the line 70 7 FIGURE 22.

7, and the portions are rotated around new axes*71' and 71", and preferably with a difierent development liquid, causing projection of a third dimensional migrationuto new R areas172,72 and 72 etc, for the pure compounds, and the components 68,68 and 68 separate into, new components 73, 73", 73 73 73 -and 73 'The other specimens do likewise as suggested by arrows 73 I In some cases it isvdesirable to isolate one channel Example :],.--Pr0 ced ure for separation-of. mixturesby.

high speed chromatography usingone type of filtervv 5 Five dyes arelemployeddn this example: i I

from another and permit the usenot only of different separation media, but. of difieren-t development liquids.

In FIGURES 21 to 24 I illustrate aseries of individually dissolved in water containing 0.2% of.=each dyeby weight. a

separate channels 42", each of, which may have theinterior crosssection as previously described, and suitably mounted on a desirably verticalshaft 21 by a hub 23' through engagernent. of hooks 23? in interlock openings 74: and clamping by bolt 75 extending through an opening 76.

The channel has near its radially inner end a reservoir" 77 which has a radially.outwardly extendingdischarge op-ening-7S-Which enters the. channel 42' andzdistributes J suitably at the center to the paper or other; radiallyi extend-Q ing strip- 46:engaged in the channel by the converging walls previously described. T he reservoir suitably has.

at the bottom a fiber glass-or other filter 80 and is covered with a cover 81 having an air bleed opening 82.

' The channel at the radialouter end has a suitable cup'or otherreceiver 83 which is hinged and under. centrifugal.

action'can swing out to a-radial outer-position as in.

It will be evident liquid and With'a difierent separation medium and of j course with difierentmaterials being separated as desired.

The material being separated in this case, as also in the.

cases previously'described, can be introduced in solution "in the development liquid or spotted on the paper or other medium as required.

' V v OPERATION In operation,- in'accordance with the present invention, the paper or other separation medium is placed in position' on therotor, and where spotting-I is to be :used the that in this case eachof the channels. can operate with ai diflferent'solvent'or other development known and unknown specimens are spotted directly op- .7

posite each other on the radial inner portions of the'strips, usinga micropipette or other suitable meansto control the specimen size. 'The particular development liquidis y then fed; and the device rotated or in many cases a succesesion of different development liquidswill be used.f-.At. 5

suitable time intervals the-operation will be stopped and.

the R areas examined and integrated comparing knowns and unknown-s.

Definitive results'have been obtained'in accordance with v the present invention intirnes of the order of seven minutes with markedly distinct separation areasand clear front and back band lines. n

a Between each run using a differentsolvent or a different substance tobe separate-d, all par-ts which contact the solvent and/ or the .material to v be, separated; including the solvent feed deviceythe grooved disc, and the solvent reservoir must be thoroughly cleaned toiremove all of the previous residue, and then be rinsed with de-ionized water.

' The center fiber glass disc wicks 5t and 51 are changed after, every three runs with the, same'solvent, and are changed whenever the solvent or the substance to be separated is changed. The separation medium, whether it be filter paper, ion exchange paper orcellulose medium,

are cut beforehand ,tothe proper Width and length to .fit

in the groove, In the preferredembodiment where. the 7 paper has apreferential fiber... direction, the. paper is' cut sothat this preferential fiber direction is radial: v

' Care should be m-adein handling the medium, and rubber gloves should be worn which are free from any-con-:

taminating. component during the cutting operation and during the setting up of the equipment. V

MethylR'edfip Methyl Orange BromCresol Green..- .BromPhenol'Bluefandii Amido Bla'ck' The mixture of dyesas previouslyfdescribed arefto be; I separated iby' Whatm-an No.11 filter paper; Eight strips;

of filter paper numbered 1' through 8 are placedin 8'dif-' ferent groove'sof the rotor, and 4 lambda ofthedye'mix ture is applied in a band running fr-omg'one' ed'gexto the:

other across the: filterfpaper 1' centimeter:fromlttheiinner j end. The. strips are then: place-din the.groovesi'ofthe;v rotor with the inner'endsfextendinginwardly,betweenthe:v two centerfiber: glass dis'cfwicks. The solvent reservoir "housing is secured in place and thesolvenhin-thiscase 0; mo'lof citric acid butter haVing apH 0513.5, "is fed from the solvent feed device. through the center reservoir: hous'ingataxrate ofijone drop ;every -:25-seconds (0.'13; ml./min. The reservoiris turned at'a; speed of approxi mately 9 00 r.p.m,*.and the rotation is continued fo'r 9 min-utes. Thediscis then quickly 's'topped by"han'd,' and f the strips of-filt'er paper are removed and scanned, in any;

suitable mannen as' Well ,known'in the;art, forrexample 1 1 using the Spinco ,Analytrol- RBi-and a deter minatio" made of-the R values 'for the r/Various dyes.

, It'was found thatin every-Cease the bands were sep-a-Y rated into diiferent areaathe ordertro'm theradialinner .4 end to the! outsi-de- -being-amido black, methyl orange,

methyl red, brom phenol blue andJbrom 'creso'l 'greenf These were compared with'controlsftor thepurpose of {a I determining the'identityand-concentration;

Example 2.9;Pr0c ed ure Jor separgti ofiyof dye mixtures I by high speed chromatography using four, dz'firentfilten The filter papers usedvwerervvlhatmajnlNo-1, Whatman I i a No. 4, Whatman3- ni-m. and schleichei gand Schuellj#598';Q Thediffer-ences are in' the density oflith'e filter. papers as wellknown in the art. Eight strips. :o-f filter V bered, and had theffollot ving compqsitionstg Two lambda of dye mixture was applied in ta band extending transversely across each stripabout l centimeter J from the radial inner end. Strips 1 through 4=received the. mixtureofthe .five dyfeszand 0.2% of methyl orange The strips were then'placed-inthe. radial groovesl-of the.

in water as -a control was applied on'stripjs 5 through .8.

rotor with 'the inner ends of x the strips, between f the two b glass d s' k 50mm, 5-111;The%solvent reseryoir was applied, and; the isolv'enniin thisaca se;consisting jof KH POg' b-ufier having a pH of 5.2; jwasgfedifromthegzsok paper were tprepar'ed ,aridInum- 1 vent feeding device at a rate of approximately one drop every 30 seconds (0.125 ml./min.). The rotor was adjusted to a chosen speed in the range between 500 and 600 rpm. and was run at this speed for 12 minutes. The strips were then removed and scanned as above described.

Very effective separations were obtained on all of the different filter papers, and the Rf values for the control were compared with those for the mixture of dyes. The best separation in this case was obtained by Wha-tman No. 1 filter paper.

Experiments similar to the above were carried out using other buffers at various pHs including sodium borate buffer, sodium citrate butter and sodium phosphate butter. A solvent consisting of 40 cubic centimeters of concentrated ammonium hydroxide and 10 cubic centimeters of n-propanol gave excellent results.

Other experiments similar to the above were carried out with Schleicher and Schuell filter paper 602, 2316 and 470. The ammonium hydroxide solvent gave scanning values as shown in FIGURE 25 for No. 1 filter paper specimen, which was scanned with the result shown at A for the density of each area when in a basic vapor and as shown at B when in an acid vapor. The upper curves plot density against position, and the lower curves C and D show the corresponding integrator values indicating the areas on the curve.

Example 3.-Prcedure for separation of dye mixtures without centrifugal forces Five dyes in a mixture as employed above and four filter papers as used in Example 2 were employed. The numbering of the strips was the same as in Example 2. The bands of dye mixture and of control were applied as in Example 2. The strips were placed in the machine in the manner previously described but the machine was not rotated. The solvent used was 40 cubic centimeters of concentrated ammonium hydroxide and 10 cubic centimeters of n-proponal, and the feed was at the rate of one drop every 30 seconds. After 60 minutes a fair separation of the dyes had taken place along the lengths of the strips, the solvent front having extended about /3 of the length of the strip at the end of 60 minutes. The strips were then removed and scanned as above described.

Example 4.Procedure for separation of amino acids by high speed chromatography Both acidic and basic amino acids are to be separated by high speed chromatography according to this example. The separation medium was weakly acidic ion exchange paper containing Amberlite IRC-SO resin, in the H plus form. Amberlite lRC-SO is a carboxylic acid cation exchange resin prepared by the copolymerization of methacrylic acid and divinylbenzene as set forth in U.S. Patent No. 2,340,111. Eight strips were numbered 1 through 8 and two lambda of the materials to be separated were spotted on the strips, 1 centimeter from the radial inner end. As an initial basis for determination of the R of the various amino acids, they were applied to difierent strips as follows:

1 Aspartic acid.

No.2 Arginine. No. 3 Glycine. No. 4 Lysine. No.5 Serine.

No. 6 Tyrosine. No. 7 Tryptophan. No.8 Valine.

Each amino acid was in a solution having a concentration of 0.02 mol in 0.1 N hydrochloric acid. The strips were placed in the grooves on the rotor with the inner ends extending between the two center fiber glass disc wicks. The solvent reservoir was placed on the machine, and a solvent in this case consisting of 0.1 M sodium acetate in water having a pH of 4.9, was fed at a rate of one .10 drop every 45 seconds. The rotor was rotated at a speed of 700 rpm. for 20 minutes, then quickly stopped by hand, and the strips were dried in an oven at centigrade, and then immersed in a 0.25% solution of ninhydrin in acetone. The color was allowed to develop in an oven at eentigrade for 20 minutes. The strips were scanned as above described and the R determined.

FIGURE 26 shows the various strips numbered from 1 to 8, with the origins at the right and the solvent fronts 83 at the left. The locations of the various components are at 84. It will be evident that the distance of travel Rf is ditferent for the various components except in the case of arginine and tryptophan, and they can readily be separated by changing the pH of the buffer.

As an alternative procedure the spots 84 at the end of the operation can be eluted from the strips and read on a suitable spectrophotometer. When mixtures of amino acids are to be separated, they are spotted on strips which are placed in channels diametrically opposite from the controls.

Fair separation has been obtained using strong acid ion exchange paper such as Amberlite IR- in the Na plus form with a solvent consisting of 0.1 M sodium acetate buffer at a pH of 3.5. Amberlite IR-120 is a sulfonic acid type cation exchange resin prepared by the sulfonation of a copolymer of styrene and divinylbenzene, as set forth in U.S. Patent No. 2,336,007.

Good separations of amino acids have also been-obtained with strongly basic ion exchange paper such as Amberlite IRA-400 resin in the chloride form of KH PO buffer at pH 7.2. Amberlite IRA-400 is a strong base or quaternary anion exchange resin prepared by the aminetion of a chloromethylated styrene-divinylbenzene copolymer according to U.S. Patent No. 2,591,573.

Good separations of amino acids have also been obtained using Whatman 3 mm. filter paper with a solvent composed of 35 cubic centimeters of ethyl alcohol, 8 cubic centimeters of concentrated ammonium hydroxide, 5 cubic centimeters of methyl alcohol and 2 cubic centimeters of ligroine.

Example 5.Pr0cedure for separation of dye mixture using starch gel Six dyes were admixed in water solution having 0.2% by weight of each of the following:

Methyl Red Methyl Orange Brom Cresol Green Brom Phenol Blue Brilliant Cresyl Blue, and Amido Black A thick paste of corn starch in water was made up. Paper strips, suitably filter paper, were applied in the bottom of the radial grooves, and the corn starch paste was poured over the paper and was absorbed by the paper and allowed to form a layer about 2 mm. above the surface. This was heated to about 90 centigrade to remove air bubbles, and the result was a smooth homogeneous gel on the filter paper.

At a position 1 centimeter from the radial outer end of the fiber glass wick elements, 4 lambda of the dye mixture was applied to each groove. The distributing mechanism was applied at the center, and concentrated acetic acid was used as the solvent, and allowed to drop into the distributing reservoir at the rate of one drop: every 30 seconds. The reservoir was turned at a speed of 200 rpm, and the operation was continued for 2 hours. An efiective separation of the various dyes was obtained.

Good results have also been secured with the above technique running overnight Without rotation, a heavy glass plate being placed directly ontop of the grooved rotor to retard evaporation.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need new and desire to secure by" Letters Patent isz in place in each channel.

artisans;

will doubtless become evident toother skilled in the art-,-

to obtain all or part of the benefits of my invention Withface.of-thecoverwill'traveldown the:surfaceitoward the- 'd ppage: of:

out copying the structure and process shown, and I, there V fore, claimall such insofar as they fall within the able spirit and scope of my claims. a Having thusidescrib'ed my invention what I claim as 1. Ina device. for liquid chromatography, rotating means havinga substantially. vertical axis of rotation and a plurality of substantially radially outwardly extending longitudinally 'extending side walls, a bottom forsupport *of separating medium, and'an open top which permits evaporation, an elongated strip 10f separating medium resting on the bottom of eachsaid channel and extending across said channel, and each said strip engaging said walls of the channel and coextending with said chann'ehand means for supplying a developing liquid to theseparating medium in each channel at radially inner portions of said strips for flow to occur. radially outwardly along'said strips and between said walls of said-channels in response to rotation of said rotatingmeans.

. 2. The device set forth lin'claim 1, wherein said walls, of each channel converge upwardly in the channel and by said' convergence hold said strip of separating medium 3. Thedevice set forth in clainrl, wherein said means for supplying the developing liquidcompriseaavesseb located adjacent'said vertical axis, orifice means for feedreason- 7 densate onto'thejsepa'rating medium; a a a 8. A componentqforq a--1iquid:;-centrifuga1 .chromato 1 graphic: deviceihaving afstatically balancedfrotor rotat+;: 7 ing on a--verticallaxis with a plurality of'radiallypnt-V. wardly extending channels therein and an'inlet adjacent 77 I to thercenter'ofthef rotor for. a supply of material. in a 1 outer edge; of the cover thus preventing liquid vehicle, said component including ahubsportion channels, said rotating means beingstatically'balanced aboutthe vertical axis,'each said'ch'annel having parallelingdeveloping liquid from said vessel, and a'fibrou dis tributor independent. of'said strips of separating medium mounted'on said rotatinig means near said axis 'and extending outward to engage each'strip near said inner end thereof, said distributor receiving developing liquid from said, orifice means.

4.-The device set forth-in claim lffurther including a hub portion surrounding said verticalaxis, and means on said hub portion communicating with the inner end of each channel for supplying developing liquid thereto, said meansfbeing centralized With respect to all of said.

channels. I a g g i 5. The device set forth in-claim 1'; whereinsaid means for supplying developing liquid comprises-separate means for supplying a ditlerent'developing" liquid tofthe separatf ing medium in each channel; 7

6.71% device of claim 1, whereinsaid innerfendsl of said strips, of separating medium .are interconuectedby' V a hub from which said "strips extend substantially radially,

andwherein the tonterends of .said .strips are intercom nected by a removable, outer rim. I

7. The device of claim 1;wherein the upper surface of the separating mediumis exposed for evaporation including a cover placed in spaced relation above said separating medium, said cover having a sloping inner surface extending downwardly and outwardly from a point above the vertical axis of the'rotating means to anouter'edge i of the said cover'disposed'beyond the outer edgexof the separating medium, whereby 'condensation of the evaporated developing liquid accumulating 'on the inner sur-.

7 stripsbeing orientedrsubstantially radially. I 1%); The component of claim8,;"Wherein1the Said .ccm'-- .ponent includesan outer rim portifoninterconnectingthe; outer: ends :of the .pervious radial strips i-n jcircurhferenz tially spaced apart'relationship'g said rim. portion being: a A readily'detachablefrom the perviousfradi-al'strips.- f l1."A cornponentfforlaliquidicentrifugale chromato-E v graphic device having a' statically balanced rotor rotat I outward while the rotor is being rotated V 1 adapted to be secured to the rotor of'the deviceadjnqent to the liquid vehicle supply inlet; a plurality. ofpervious separating mediumstrips 'extendingradially. outward from y i i and integrally connected; with said hub. portion, each pf. I s 1 said pervious stripsbeing terminally spaced from onean -j other and adapted to fitvvithin the channels and to tr'ans-- mit the liquid vehicle 'radially' outward while the'rotor, is being rotated.

9.2 The component officlaun'JS, whe reinisaid compo- V V nentisafibrous;materi'al;thefibers ofthezper-vibu's radial f ing on a-verticali axisr andan inlet'adjacent to the; center Reterenc es-Eited by thQIQ im Heni'i i v i 5UNITEDJSTATES"-PATENTSI r 'FORElGN, PATENTS 525,224; 52/47. Great Britai r 1; 811,627 4/59 Great B ritain.1; l w 5' q a I OTHER -REFERENCES;=; 1

, V Caronnai La-Chimica e L Ind'ustria vfolume .'a,7,l pp. 1131 l4.. V a 77 'EJLederer: Chromatography, Elseview lublishiri'g; Co,

New York, Second Edition, 1957;";

REUBENFRIEDMAN Brin'z iry Examiner.i V

HERBERT'L. MARTIN, Examiner. 

1. IN A DEVICE FOR LIQUID CHROMATOGRAPHY, ROTATING MEANS HAVING A SUBSTANTIALLY VERTICAL AXIS OF ROTATION AND A PLURALITY OF SUBSTANTIALLY RADIALLY OUTWARDLY EXTENDING CHANNELS, SAID ROTATING MEANS BEING STATICALLY BALANCED ABOUT THE VERTICAL AXIS, EACH SAID CHANNEL HAVING PARALLEL LONGITUDINALLY EXTENDING SIDE WALLS, A BOTTOM FOR SUPPORT OF SEPARATING MEDIUM, AND AN OPEN TOP WHICH PERMITS EVAPORATION, AN ELONGATED STRIP OF SEPARATING MEDIUM RESTING ON THE BOTTOM OF EACH SAID CHANNEL AND EXTENDING ACROSS SAID CHANNEL, AND EACH SAID STRIP ENGAGING SAID WALLS OF THE CHANNEL AND COEXTENDING WITH SAID CHANNEL, AND MEANS FOR SUPPLYING A DEVELOPING LIQUID TO THE SEPARATING MEDIUM IN EACH CHANNEL AT RADIALLY INNER PORTIONS OF SAID STRIPS FOR FLOW TO OCCUR RADIALLY OUTWARDLY ALONG SAID STRIPS AND BETWEEN SAID WALLS OF SAID CHANNELS IN RESPONSE TO ROTATION OF SAID ROTATING MEANS. 